Vacuum-tube filament



Feb. 5, 1929. 1,700,855

H. M. RYDER VACUUM TUBE FILMIBNT Filed April 7. 1922 WITNESSES: V INVENTOR Patented Feb. 5, 1929.

UNETED STATES HARRY M. RYDER, OF WILKINSBURG, PENNSYLVANIA, .ASSIGNOR TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATIUH 6 PENNSYLVANIA.

VACUUM-TUBE FILAI /EENT.

Application filed April 7, 19%.

My invention relates. to evacuated electric devices of the three-electrode type and particularly to an improved llltllllQilI-SPIlllg ocsign.

in its hroad aspect, the principal ohject of my invention is to provide a filament spring of simple, compact and rugged design having highly desirahle operating charac cristics which admit of material economies in the time necessary for manufacturing tubes enihodying the same.

More specifically, another object oi my invention is to provide a flexible spring which admits of an extremely large movement incident to the expansion and contraction of the filament and which substantially eliminates all side motion or vihration ot the filament.

Another object of my invention is to provide a filament spring which employs a minimum length of material, whcrehy the potential drop thereacross is decroase'l. The latter is of importance in view of the relativ lfv' low exciting potentials applied to the filament terminals of the tube. embodying my invention.

A further object of my invent on is to provide a filament spring which tends to minimize vihration of the filament, s caused by a slight jarring of the containing envelope.

In the design and manufacture of a vacuum tnhe adapted to opera e on an extremely low power consumption. as, for instance, a quarter of a watt or less, it was tonnd necesary to redesign ererv essential element ot' the usual higher powered llllH, strut-t ure. ln IPEloral. the several elements must he very closely spaced. hence requiidno a filament spring: oi special design adapted to accomplish the results en'ihodied in the above-meritioned ohjet-ts and others hereinafter mentioned.

Alter considerahle experimental work, a filament spring was developed which accomplished the desired results. The spring comprises a middle portion and bent-hack end portions forming; a figure somewhat similar to the letter S. A carrier rod and a filament may he secured, respectively, to the free ends of the bent-back portions.

Other objects of my invention, as well as details oi construction, whereby my invention may he practiced, will he apparent from the following description and claims when read in connection with the accompanying drawing, wherein:

Serial ilt). 550 435.

The single figure is a front elcvational view of an evacuated electric device emhodving mv invention, a portion of the containing walls being; broker. away.

in the single figure ol' the drawing is shown a vacuum-tithe device 1 embodying a design which admits oi filament pow er consumptitins ol less-1 than one-fourth oil a watt, as compared itn power consiiinptions of from three to c watts in the ordinary type of vacuum he. The vacuum-tube device comprises an closing envelope 2 having a re-entrant por at one end, terminating in a support- 5 press 4.

A filament spring which may be made ol such materials as tungsten or molybdenum, comprises a central portion (3 and upper and lower hent haek portions 7 and 8, respectively. The nature ol the bonds 9 and 11. is such as to provide a spring action tending; to oppose mot ion of the several bent-hack portions thereahout. The upper bent-hack portion 7 is somewhat longer than the lower portion 8 and rigidly secured to a carrier rod 12 in such manner that the several portions of the spring are disposed in a common plane. l he carrier 12 may he extended through the pron 4: and he provided with a terminal con-- doctor 13 elect ically connected thereto.

A filament it has one end rigidly secured to the remaining free end ol the lower bent-hack portion 8 of the filament spring 5 through a nickel-steel connector l4 and the tlnr cnd rigid y secured to a carrier rod to t-mhedded in the press l throuc h a nickehsleel connector if). The nicltelaieel connectors it and 1h constitute the siihjiert matt r oi a Patent 1.6142654 of Marl: li vder, Serial No. Slthlhth iled ilovemher T. ii ri. and patented Jan uary 192T, and assigned to the Westinghouse Electric and Manu'lacturina Company. Th carrier rod 15 may he extended through the press and provided with a terminal conductor 16 electrically connected thereto to serve as the remaining supply lead for the filament 14. In the particular type of tube shown, the filament ll composed ot a. plat i num strip approximately one-eighth as thick as fine tissue paper and one one-hundredth of an inch wide. The strip is coated with a very thin iaver of certain oxides adapted to l'orn a special type of lVehnelt cathode.

A grid member 17 of helical shape is dis posed ahont the filament l4 and is carried hv a structure 18 which is supported from the lit) The structure 18 may be extended it: press 4 by means of a conductor 11) eleetrit-ally connected thereto to provide an external circuit terminal for the grid.

A eylindrieal anode or plate member :21 i\ so iisponed as to eoinpletely surround the grid and filament elements and snri-or'ted by carrier rods prew; at. thro ngrh ti and :23 extending from the 1 and rigidly supported to 05mm points on the anode 721. The earrier 1m may be en ded thrtngb the prees to provide an external ei inertion by ineana of a rondnvt r it 1 5: one end eleetrirat y ronneeied thereto.

'hen the filament 1'1, esz nn it is tonnd that all Stilt motion ltia snbstantiall hzninatm t eonxpennating torew ti /n of the spring \Yhile. l have shown only one rnfaatiriei-t of my invention, for the pin-pow ot do, in the saline and illustrating the n' tl'iereot', it is capable ot rario a moditieations Without departing; tro1n the spirit of my invention a nd i des-rire, therefore. that only sue-b. limitations abad be imposed thereon as are indicatei't in the appended (lililHS or demanded by the prior art.

I elaini as my invention:

1. In a threeelenlent' eleet tnbe romprising a linearly extent tin r tiiainent, a cylindrical grid and a larger cylindrieat plate, ail. eoneentri ally (lisp l 'n elnse relationship, means for supporting the titainent eoinpri in a supporting n a, t earri it by id prey; and tttaehed to the nearer end of waid filament, a aeeond rod =arried by and preaa and extending onaide of said eyl driral plate to a point beyond the farther ear.

the

tnnnent. and a spring member eonipri 1;; a substantially Hrargbt central portion and bti ei'nbstantiz-dly straight it-bael; end portie a, at o1 Htlltl PUI'tUEDS lying in s-nbstantiatty the an no plane, one of said bentlmek end portions being; longer than lli( central portiosn and the other ot' said bent-bark end portiozm being amn'oxiniately onwhalt' a long am said rent a! portion, said longer end portion haring it: free end attached to said second rod, and said halt-length end portion having ita tree end attaehed to said titannnt.

in an ele'ctron tube eoniprieing a linearly enter ting: tiiaioenti -=tantiatly eoneentrie eytindrieat dinposed in close relatiomhio thew-n means tor supp rting be tilaznent t= ai i" 7 r ng" prws rod earried by eaid attarhed to l d a wJ-it'lltl rod w and e; Qnni 'nlts-itlt ot' mlrt beyond Titi rte

tint d by ore net. l portion b 1;; longer 1 l and the other otl i being approxn lllll 1 :natrly z :m long a:--, said ventral porend portion having it; tree l thalt end attioir,

at linear tila- Faad filament,

tof and eleu ndee: inel i went, and m ans:v tor Hi eompriaing a altandard a "ext tea" and an B+"--1g,=ed Fin 1 ext nding from Stllil standard beyond the atner mate of aid eleetrmlea and term nating at said Ellan a eet'rode map of conven- V2 i-tandard one side of said elevan -sba1md spring er ending tron: said standard beyond the other side of said electrodes and terininatin g at said tilanaeat; raid spring eonnn'ining three enbstantially etraigrht portions and eonneeting bendr; two of aaid saw it portions be ng longer than the TI'ttt(r--,t diameter of the outer elevtinde,

in tmtimony whereot l have hereunto sub srribed m3. name this Ztati av ot Mari-b 193;,

HARRY M. RYDER.

for supporting said liianient. 

